Improvement in school-desks



M. LANCASTER.

SCHOOL DESKS. l Nn.183,4:02. v Patented 0ct.17, 1876.

N. PETERS, FHCTO-LITHOGRAPHER, WASNINGYONA D C.

NITED STATES PATENT OFFICEo MORRIS LANCASTER, OF RICHMOND, INDIANA.

IMPROVEMENT IN SCHOOL-DESKS.

Specification forming part of Letters Patent No. 183,402tdated October17, 1876; application led June 19, 1876.

To all whom 'it may concern Be it known that I, MORRIS LANCASTER, ofRichmond, State of Indiana, have invented an Improvement in Falling-LidSchool-Desks, of which the-following is a specification:

This invention relates to certain improvements in school-desks; andconsists in a paWl-'secured to the standard supporting the desk, andadapted to engage with or be disengaged `from a stop (with which itregisters) automatically by the movement of the lid of the disk upon itshinge or pivot, as Will hereinafter more fully appear.

In the drawing, Figure l represents an end elevation of my improveddesk; and Fig. 2, a vertical sectional view, showing the Workingmechanism ofthe same.

The letter a represents the desk-lid; 11,rhe desk-body, and c thestandards by which the same is spported. The desk-lid is secured, asusual, to the arms a', pivoted or hinged to the inside of the standards.The inner ends of' said arms are enlarged, and either or both of themprovided with a shoulder, F, the object of which will be hereinafterexplained. The rear end of the arm is curved, and along such curvedportion, on the face of the enlarged portion of the arm, is formed aninclined cam, commencingat the shoulder and terminating in a thin edge'at the upper edge of the enlarged portion of the arm.

The letter d represents a stop, consisting of a straight bar looselysecured at its rear end to the body b, and extending forward to the rearof the enlarged portion of the arm a. Said rod is capable of a slightlaterall movement, and is kept pressed to the standard by means of aspring, E, securely attached to the lower part of the same. The letter Frepresents a stop setting over the bar d, to prevent it from beingthrown upward out of position.

The operation of my invention is as follows:

When the lid is down in the position shown at a3 the end of the roddsets in the recess under the lid of the desk, below the front it is rstelevated to the position indicated by a4, in which position the end g ofthe inclined cam at the rear of the enlarged portion ofthe arm fallsunder the bar, When the lid can be depressed, the end of the bar beingpressed outwardly by the cam, causing the shoulder to pass clear of-said bar, which rests against the face of the enlarged portion untilthe lid is fully dropped, when it falls under the curved front part ofsaid enlarged portion, being forced therein by the action ot' the springE, in which 'position it is ready to again engage the shoulder F Whenthe lid is again elevated.

I do not claim a hinged lid in combination with a pawl or dog attachedto the same, and registering automatically with a stop on the standardby the operation of the lid, as such forms the subject of'a separateapplication by me, filed June 28, 1876.

What I claim, and desire to secure by Letters Patent, is

l. The pawl d, securedl to the standard which supports the desk, andadapted to engage with or be disengaged from a stop automatically bythemovement of. the lid of the desk on its hinge or pivot, substantiallyas described, for the object herein set forth.

2. The horizontal bar d, pivoted at its rear end to the standard ofl thedesk, i-n combination with the spring E and lid-supporting arm a',having the cam-surface and shoulders or stops g and F at its rear end,substantially as shown and described.

MORRIS LANCASTER.

Witnesses:

. M. P. WRIGHT, I. LANCASTER.

